title: Enhancement of human peripheral blood mononuclear cell transplantation-mediated bone formation.
abstract: Recent studies have demonstrated the existence of osteoblast progenitor cells in circulating blood. Here we show that local delivery of bone morphogenetic protein-2 (BMP-2) to cell transplantation sites induces in situ osteogenic differentiation of transplanted human peripheral blood  mononuclear cells (PBMNCs) and enhances in vivo bone formation mediated by PBMNC transplantation. Human PBMNCs were seeded on scaffolds with or without BMP-2 and implanted subcutaneously into athymic mice. Nonseeded scaffolds with BMP-2 were also implanted. Eight weeks later, radiographic  and histological analyses showed that the PBMNC + BMP-2 group had undergone much more extensive bone formation than either the PBMNC group or BMP-2 group. Only the PBMNC + BMP-2 group expressed human Cbfa1, osteonectin, and osteocalcin, suggesting in situ osteogenic differentiation of and  bone formation by transplanted human PBMNCs, while the other groups did not express these genes. This study provides a method to enhance human PBMNC transplantation-mediated bone formation.
authors.affiliation: Department of Bioengineering, Hanyang University, Seoul, Republic of Korea.
authors.forename: Hee Seok
authors.initials: HS
authors.lastname: Yang
authors.forename: Ga Hee
authors.initials: GH
authors.lastname: Kim
authors.forename: Wan-Geun
authors.initials: WG
authors.lastname: La
authors.forename: Suk Ho
authors.initials: SH
authors.lastname: Bhang
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Lee
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Byung-Soo
authors.initials: BS
authors.lastname: Kim
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000166:cytology / Q000000981:diagnostic imaging / Q000378:metabolism; D002454:Cell Differentiation; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D020007:Implants, Experimental; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000637:transplantation*; D051379:Mice; D010012:Osteogenesis / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055114:X-Ray Microtomography; D055815:Young Adult